Choosing a pool can be stressful. So can choosing a wallet. Litecoin itself is just about unhackable, so long as no pool gains more than 50% of the network’s hash power, but every additional layer between you and the litecoin network requires a measure of trust and potentially threatens your security.
Which is why the process for setting up a worker is such a nice respite: basically no precautions are required. A worker represents a computer or mining rig on a pool. You might have just one, or you might want to set up several, each corresponding to a different machine. Each worker will have a username (all housed under your username at the mining pool) and a password. You can make the password “1234” or “password,” if you want. If someone compromises your worker, all they can do is mine cryptocurrency for you.